(a) Field of the Invention
The present invention relates to a four wheel drive vehicle with an anti-lock braking system comprising front and rear axles coupled together by a power transmission assembly capable of transmitting a braking force acting upon the front wheels to the rear wheels, a power unit connected to the power tranmission assembly, and a hydraulic braking system for controlling the hydraulic pressure applied to a brake for each of the wheels, the hydraulic braking system including an anti-lock control device adapted to control the hydraulic braking pressure to reduce the same and prevent locking of the wheels.
(b) Description of the Prior Art
There has been a continuing development process with respect to improving various aspects of the characteristics and running performance of four wheel drive vehicles in travel on road surfaces which have a low coefficient of friction, and in addition, attempts have been made to equip such four wheel drive vehicles with anti-lock braking systems.
However, a number of problems occur in cases where an anti-lock braking system as used in a conventional two wheel drive vehicle is employed in a four wheel drive vehicle. Specifically, in a four wheel drive mode in which the braking force acting on the front wheels is transmitted to the rear wheels, interference occurs between the front and rear wheels, so that it is difficult to achieve a satisfactory anti-lock effect.